I have and still regularly drive from Philly to all over Michigan. My road trips are usually 600 - 800 miles, and I'd say that 800 miles reaches the limits of how far one wants to drive in a single day. Yeah sure, people can go further per day, but I know that last 100 miles of the 800 mile run every August is done on adreneline and caffeine.
My goal is always to average 60 MPH (including stop time) on long trips. Short term runs can be quicker, but you get killed when you stop for pee, food, soda, and leg stetching. I always stop at the next rest area if I feel groggy and take a 20 or so minute nap in the car. Had a few scary drowsy driving experiences.
I don't trust Mapquest at all. For example, the rehersal dinner for the wedding I was in last weekend was in Temperance, MI (or Ida, I forget exactly). Mapquest told people to go into Ohio to get there, even though the proper exit is 11 miles north of the OH/MI border on I-75. Half hour out of the way. Get a road atlas (the trucker's versions are awesome for current details on construction, tolls, etc.) and plan it out yourself. It's not that hard.
I personally use Streets 98 on CD for trip planning (time to update). I map out the route and then print the various maps I need. I also carry a road atlas in the car for emergency use.
AAA triptiks are good, but don't always have the best route. I knew a girl in HS that did triptiks for her job, and she showed me one she was doing for Philly to Ocean City, MD. She took the more major roads and added 45 minutes to the drive, instead of the preferred route on a smaller Delaware highway.